The circulation of blood in the femoral head is often destroyed at a dislocated fracture. If there is inadequate circulation of blood, a necrosis of the femoral head will develop and prosthesis implantation is the most likely course of treatment. Inadequate blood flow in the neck of the femur may lead to inadequate healing of the femoral head after a fracture and may cause osteonecrosis, a disease that results from loss of blood supply to the bone where the bone tissue dies and may eventually collapse. If a bone involved in osteonecrosis is near a joint, e.g. the femoral head, it often leads to the collapse of the joint surface. On the other hand, if there is adequate circulation of blood in the femoral head, the femoral head remains alive and in this way the fracture is capable of healing. Here, the most likely surgical solution is to perform osteosynthesis. Thus, the determination of whether there is adequate circulation is an important step in the overall treatment regimen.
A reliable method for measuring blood flow in the bone before and during surgery will impact treatment selection, which will likely result in an improvement of the clinical outcome, minimization of cost and prevention of long term disability. Furthermore, accurate measurement of blood flow is important for orthopaedic research due to close correlation of the flow with bone formation and mineral deposition. Accurate measurements may also allow secondary predictions of bone activity in other bone disorders.
Instruments for measuring the blood flow in bones such as the femoral head after a femoral neck fracture are already known from e.g. WO 2007/126888 and WO 2008/135798.
These prior art blood measuring instruments however, have a rather complex construction and are circumstantial to use.
Thus, there is presently a great need for an instrument that can give an accurate and more immediate determination of circulation flow and that is of a simple construction and easy to use.